This invention relates to a rivet head caulking machine provided with a rivet detector.
As shown in FIG. 4, in a prior art caulking machine, after placing a part to be worked having a plurality of rivet shanks passing therethrough on a table 2 of a column 1, a piston shaft 4 is lowered by a cylinder 3 mounted on the column 1.
A spindle 6 is rotatably and coaxially mounted to the piston shaft 4. It is driven by a motor 5 mounted on the top end of the piston shaft 4. On the bottom end of the spindle 6 is mounted a rivet head forming tool 8 having a forming shaft 7 for forming a rivet head on the rivet shank.
The work piece having rivet shanks passing therethrough to secure parts together is set on a table which is moved in both X and Y directions so that the rivets will come under the head of the caulking machine one after another.
Since this machine is not provided with means for detecting the existence of a river shank, it is impossible to check whether a rivet head is being formed or the spindle is idling with no rivet in place. Therefore, an operator had to check whether or not there was a rivet shank in place. Should the rivet head forming tool lower onto the work with no rivet shank present, the work piece might get marred.
If the parts to be secured together have a great number of rivet shanks passed therethrough, such visual checking is quite troublesome and thus is extremely inefficient.